Vestigial Structures- Flightless Birds

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Transcript of Vestigial Structures- Flightless Birds

By Renato Belouche & Nina Su Vestigial structures Discovery There are probably over a hundred thousand species of birds that have wings that can fly. Flightless birds, such as penguins and ostriches, also have wings, yet they are unable to fly. What makes them different? Has evolution changed the way their wings worked? Evidence of Discovery The wings of ostriches, emus, and penguins are good examples of vestigial structures in birds. These birds in fact have wings, though they cannot use them to fly. This is because their ancestors had wings. Some birds became flightless because they grew too large and heavy, while some lost it due to the fact that they lived in predator free environments and being good flyers was no longer an enforced adaptation. Others had new niches that resulted in them evolving non-flying lifestyles (like penguins).Unlike many other creatures with vestigial structures, many of the flightless birds do not have a common ancestor. Each species individually lost its flight after diverging from ancestors that did have the ability to fly. Definition of a Vestigial Structure: An anatomical feature that no longer seems to have a purpose in the current form of the given species. Works Cited:Informationhttp://evolution.about.com/od/evidence/g/Vestigial-Structures.htm?r=ethttp://www.sciencedaily.com/releases/2008/09/080903172152.htmhttp://news.nationalgeographic.com/news/2010/01/10201-extinct-giant-birds-flight-dinosaurs/http://phys.org/news186047701.htmlhttp://www.pbs.org/lifeofbirds/evolution/Imageshttp://spack17.blogspot.com/2010_01_01_archive.htmlhttp://www.ilikewallpaper.net/ipad-wallpaper/Jumping-Penguins/2203http://en.wikipedia.org/wiki/Penguinhttp://commons.wikimedia.org/wiki/File:Flying_birds_at_Sacramento_National_Wildlife_Refuge.jpghttp://www.rootideas.com/2009/03/birds-and-their-skeleton/http://geology.cwru.edu/~huwig/catalog/slides/695.I.7.jpg This means that the organ or structure had some use to previous ancestors, but it is almost useless now.

The reason that vestigial structures exist may be due to lack of evolution. Yet this proves that organisms have evolved to live without the vestigial structures. vs Also, the structure of regular bird wings and flightless bird wings are very similar.